Process of producing metal-powder particles of spherical shape



Jan. 15, 192:1,

- Y .A j 1,699,205 Y E. PQDYSZUSE Alf' Pnocss oF' Pnonucme umm. POWDER nnrrcnss or' sPHERIcAL SHAPE Filed-July' 16, 192e" Patented Jan. 15, 1929'.

UNITED STATES PATENT- OFFICE.

EMIL ronszrrs, E BEREIN-ERIEDBICHSHAGEN, AND Enwm KRAMER, or BERLIN,

GERMANY, AssreNoEs v'ro HAR'rsr-orF-METALI. Ax'rIENGEsELEscHArT (HAME- TAG), 0F BERLINPCOPENICIK, GERMANY.

PROCESS OF 'IPRODUCINiG `METALPOWDER PARiTICLES 0F SPHERICAL SHAPE.

' Application" mea my 1s, 1926, serial No.

My invention relates to the production of metal powder particles and has for its special object to produce metal powder particles constituting hollow spheres.

5. By means 9i this invention it is possible to produce mh'ectal powder whose particles measure about 1A), nun. to 1/100 mm. and less, and such powder can be made from the most heterogeneous kinds of metal and even 10 from ingot-iron of great strength.

Metal powders of this kind are required for the manufacture of pressed bodies, as for example dynamo brushes, sliding cout-act members and the likeV which are made from a mixture of graphite and metal powder, or for magnet cores of induction coils and the like that consists of a mixture of metal powder and insulating substance. The powders used hitherto for these purposes consisted of metal lakes of more or less irregular shapes. A powder in accordance with the present invention, as compared with those known powders has the advantage that the roundness o its particles or grains in itself causes the grains 'to lie closer together so that smaller pressures are required in making pressed bodies from them. A further advantage that accrues.

from the formations of the grains is that individual grains are in the form of hollow bodies. When 'this hollow-grain metal powder is used together with, graphite for making pressed bodies that are to be used as sliding Contact members, the hollows in the metal grains become iilled with graphite so that each .grain carries it'sown lubricant. When the pressed bodies are used for bearing bushings the hollows in the grains, so far as they are not lled with graphite, will receive lubricating liquid. In magnet cores, the hollow metal grains give smaller electrical iron losses than solid grains, even if the grains are squeezed to such an extent that the hollows in them are practically closed. It is thus seen that the novel metal powder offers many advantages in various technical applications.

Another important point is that the novel process described herein constitutes the irst means of any kind for producing a metal .powder having round or spherical grains of the aforesaid size.

The metal powder .in accordance with thel present invention is produced from powder 4continued the outer edges of the grain are to such an extent that its cavity has the 'the process there is.continued, the particles 122,786, and in Germany october 10, 1925.

whose rains more or less have the shape of small akes. c

The invention is illustrated in the drawing in which Figs. 1 to 3 show the steps in which the flakes are converted into spherical hollow grams.

Fig. 4 is a section of a grain rounding device and n Fig. 5 is a section through Fig. 4.

Fig. 1 is a section of a flake-shaped powder. In accordance with the invent-ion, the edges of the grain are turned over so as to form a minute troughor basin-shaped body or grain (Fig. 2). as this process is .rounded more and more, until .at last a grain in the shape of a hollow sphere as shown in Fig. 3 is obtained. This treatment of the grain may be continued, until it is squeezed form of slit. It will, however, generally be preferable not to continue the treatmentup to this point. i The process of shaping the powder particles as illustrated by Figs. 1 to 3 may be carried out with the aid of various types of machines. A very simple machine that may be used for this purpose is that shown in Figs. 4 and 5. It consists of a casing 2 with a lid 3, a shaft 1, journalled in a wall of the casing and arms 4 and 5 attached to the shaft and having'broad ends or flukes 6 and 7. A quantity of flake-shaped metal particles only partly .filling the casing 2 is inserted into it through closable openings (not shown) and the shaft 1 carrying the arms 4 and 5 is then revolved at a high speed so as to lin'g the -particles against the inner walls of the casing and cause them to roll against said walls. The particles are 95 also flung against each other. After a while, they will assume the' shape indicated in Fig. 2 and then gradually are converted into hollow spheres as shown in Fig. 3. If

are squeezed or compressed still more, so that their cavities are reduced into narrow slits, the powder thereby becoming comparatively heavy.

1. The process of imparting to metal powder particles spherical shape, which consists in gradually turning over the edges of Hake-shaped particles, and by continuing ing them in the same operation into said `operation finally .converting the particles into hollow spheres.

2. The process of imparting tometal 5 powder particles spherical shape, which consists in gradually turning over the edges of Hake-shaped particles, and finally bendspherical shapes.

In testimony W signatures.

hereof We have aixed our 10 EMIL PODSZUS. ERWIN KRAMER. 

